in reply to Re^2: OT: Finding Factor Closest To Square Root
in thread OT: Finding Factor Closest To Square Root

Programming F(n) for benchmarking purposes is interesting. However, the fastest way of all is probably: 
F(n)= integer nearest (1/sqrt 5)[(1+sqrt 5)/2]^n

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This isn't perl, but it would only take a line. (If n is extremely large, the exponentiation might become inaccurate, though...)
chas

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Re^4: OT: Finding Factor Closest To Square Root
by QM (Parson) on Feb 21, 2005 at 01:26 UTC
    Programming F(n) for benchmarking purposes is interesting. However, the fastest way of all is probably: 
    F(n)= integer nearest (1/sqrt 5)[(1+sqrt 5)/2]^n

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    Yes, but I'd like to understand for myself why various approaches are slower. Which means I have to find a number of independent approaches.
    If n is extremely large, the exponentiation might become inaccurate, though.
    That's why you use arbitrary precision, like one of the Math::Big* modules.

    -QM
    --
    Quantum Mechanics: The dreams stuff is made of

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